Statins are group of drugs used for lowering cholesterol level in human bloodstream in order to prevent cardiovascular diseases. Statins possess 3,5-dihydroxy acid side chain with two chiral canters which are responsible for achieving the main function of the drug. Synthesis of statin side chains is a challenge due to high demands for chemical and stereochemical purity. In this work a biocatalytical oxidation of α-chloroaldehyde (lactol) was carried out catalyzed by oxidoreductases in order to produce the statin side chain. For this purpose, enzymes aldehyde dehydrogenase (AlDH) and ketoreductase (KRED) were tested. Since the oxidoreductases for its activity demand the use of coenzyme NAD(P)+ which need to be regenerated, the enzyme NAD(P)H oxidase (NOX) was used for its regeneration. The kinetics of all used enzymes was examined. Oxidation of lactol catalysed by AlDH was described by double-substrate Michaelis-Menten model with include substrate (NAD+) inhibition and with competitive inhibition by product (NADH). The kinetics of the same reaction catalysed by KRED was described by double-substrate Michaelis-Menten model with substrate (NADP+) inhibition and with competitive inhibition by product (NADPH). In the reaction of coenzyme regeneration, the kinetics of NOX was described by Michaelis-Menten model with competitive product (NADP+) inhibition. Beside kinetic measurements, the influence of the aldehydes on the stability of the AlDH, KRED and NOX was examined. Mathematical model of the process was developed and was validated by carrying out the reaction in a batch reactor. Experiments of lactol oxidation catalyzed by enzyme AlDH and KRED was carried out with coenzyme regeneration. As the substrates purified lactol as well the crude lactol, produced in the reaction of double aldol addition of acetaldehyde and chloroacetaldehyde catalyzed by 2-deoxyribose-5-phosphate aldolase (DERA) were used.